(1) Field of the Invention:
This invention relates to locking devices for use on equipment having hydraulic pistons and cylinders such as bulldozers and back hoes or the like.
(2) Description of the Prior Art:
Prior art devices have used a number of different safety supports for holding dump truck beds in up position. See for example U.S. Pat. Nos. 3,813,124, 3,157,435, and 3,135,555.
In U.S. Pat. No. 3,813,124 a safety prop for dump trucks is shown wherein an elongated tubular member is pivotally secured at one end between the truck bed and the truck frame thereby locking the truck bed in extended or up position.
In U.S. Pat. No. 3,157,435 a safety prop for dump trucks is shown having a spring loaded telescopically extensible tubular member positioned between the frame and the bottom of the dump bed.
In U.S. Pat. No. 3,135,555 a safety guard is disclosed wherein a tube is positioned around the rod of a hydraulic piston and cylinder preventing the dump truck bed from falling from the up position while the truck is being worked on.
In applicant's device a split cylindrical sleeve having an annular flange at one end and a pair of outwardly extending arms at the other is positioned over the extended rod portion of a hydraulic piston and cylinder assembly on the bottom of a back hoe attachment or like equipment to prevent the raising of the same from engagement with the ground thereby preventing movement of the tractor.